Integrated paper cargo pallet

ABSTRACT

This is a pallet as might be used to support cargo during that cargo&#39;s transportation or storage. The pallet is constructed of paper or functionally equivalent sheetstock. The pallet design involves a central platform or deck constructed of a honeycomb filler supported by a number of footblocks holding the central platform off the floor. The bottom of the pallet is covered by a combination of sheets patterned in such a way that the legs supporting the central platform are integral with that central platform; that is, the footblocks (or legs) do not have a seam at their juncture to the central platform. Desirably the lower portion is formed of two sheets; one sheet (&#34;the bottom cover&#34;) is cut and folded in such a way that the legs and the surface adjacent the bottom of the central portion are of the shape in which the pallet is finally used. The other sheet (&#34;lower facing sheet&#34;) is of the general size and shape of the bottom with cutouts allowing the footblocks (covered by the bottom cover sheet) to protrude through that lower facing sheet. It is positioned adjacent the bottom surface of the central platform. The upper surface of the central platform is covered with a generally continuous sheet (&#34;the upper facing sheet&#34;). The upper facing sheet may be a corrugate or heavy stock paper depending upon its ultimate usage. To enhance the torsional and deflective strength of the central platform and thence that of the pallet, a corrugated sheet may be used as the upper facing sheet and positioned so that the corrugations of the upper facing sheet and those of the lower facing sheet are not parallel. Additionally, the various corrugated sheets may be folded over the edges of the honeycomb core and fastened to another other surface.

FIELD OF THE INVENTION

This invention is a pallet as might be used to support cargo during thatcargo's transportation or storage. The pallet is constructed of paper orfunctionally equivalent sheetstock. The pallet design involves a centralplatform or deck constructed of a honeycomb filler supported by a numberof footblocks holding the central platform off the floor. The bottom ofthe pallet is covered by a combination of sheets patterned in such a waythat the legs supporting the central platform are integral with thatcentral platform; that is, the footblocks (or legs) do not have a seamat their juncture to the central platform. Desirably the lower portionis formed of two sheets; one sheet ("the bottom cover") is cut andfolded in such a way that the legs and the surface adjacent the bottomof the central portion are of the shape in which the pallet is finallyused. The other sheet ("lower facing sheet") is of the general size andshape of the bottom with cutouts allowing the footblocks (covered by thebottom cover sheet) to protrude through that lower facing sheet. It ispositioned adjacent the bottom surface of the central platform. Theupper surface of the central platform is covered with a generallycontinuous sheet ("the upper facing sheet"). The upper facing sheet maybe a corrugate or heavy stock paper depending upon its ultimate usage.To enhance the torsional and deflective strength of the central platformand thence that of the pallet, a corrugated sheet may be used as theupper facing sheet and positioned so that the corrugations of the upperfacing sheet and those of the lower facing sheet are not parallel.Additionally, the various corrugated sheets may be folded over the edgesof the honeycomb core and fastened to another other surface.

BACKGROUND OF THE INVENTION

A pallet is a portable, horizontal, rigid, platform used as a base forassembling, storing, stacking, handling goods as a unit load.Conventional pallets are typically constructed of wood and are made bystapling or nailing a number of boards (known as "deckboards") at theirends to a number of continuous solid boards (known as "stringers"). Theupper set and lower set (where used) of deckboards thereby form an openarea defined by the thickness of the stringers. This opening is used toaccommodate a fork lift or hand truck. In this way the pallet may bemoved from place to place by lifting the pallet and its load off thefloor.

The vast majority of all pallets used in the U.S. are constructed ofwood, but wood pallets have many disadvantages. Labor and material costsfor wooden pallets have increased faster than inflation. Because oftheir expense, the pallets are often reused or returned to their placeof origin. The cost of returning empty pallets to their owners isobviously high. Additionally, the average weight of a wooden pallet isabout forty pounds. Since shipping costs are usually tied to the weightof the goods shipped, the cost of shipping is increased by the weight ofthe pallet. Indeed, pallets are sufficiently heavy that smallerwarehouse workers are able manually to move the pallets only with somedifficulty. Wooden pallets are often damaged during use and, because ofthe pallet cost, must be repaired if possible or disposed of. Dependingupon the industry involved, pallets may be used between two and fourtimes before they are disposed of. Disposal of any solid materialsincluding broken pallets is an increasingly difficult and costlyproblem.

My invention is a pallet constructed of paper involving a centralplatform or deck constructed of a honeycomb filler. The bottom of thepallet is covered by a combination of sheets (which may be corrugate)which are patterned in such a way that the footblocks supporting thecentral platform are integral with that central platform; that is, thefootblocks (or legs) do not have a seam at their juncture to the centralplatform. Desirably the lower portion is formed of two sheets; one sheet("the bottom or lower cover") is cut and folded in such a way that thelegs and the surface adjacent the bottom of the central portion are ofthe shape in which the pallet is finally used. The other sheet ("loweror bottom facing sheet") is of the general size and shape of the bottomof the central platform with cutouts allowing the footblocks (covered bythe bottom cover sheet) to protrude through that lower facing sheet. Itis positioned adjacent the bottom surface of the central platform. Theupper surface of the central platform is covered with a generallycontinuous sheet ("the upper facing sheet"). The upper facing sheet maybe a corrugate or heavy stock paper depending upon its ultimate usage.To enhance the torsional and deflective strength of the central platformand thence that of the pallet, a corrugated sheet may be used as theupper facing sheet and positioned so that the corrugations of the upperfacing sheet and those of the lower facing sheet are not parallel.Additionally, the various corrugated sheets may be folded over the edgesof the honeycomb core and fastened to another other surface. In additionto the inherent strength and low cost of my pallet, by careful selectionof construction materials, my design may be completely recycled as paperwithout separation into constituent parts.

There are a number of pallet designs which are made mostly of paper.

For instance, U.S. Pat. No. 3,661,099, to Shelor, shows a paper shippingpallet having a deck having a core section made of small strips cut fromsingle, double, or triple wall corrugated paper board sheet stock gluedface to face. Sheets of corrugated are glued to the longitudinal edgesof the composite core. The core and facing sheets are desirably of aspecific size of corrugated sheets, i.e., having a size "A" flute orbetter. The legs of the pallet appear to be wooden blocks.

U.S. Pat. No. 3,650,459, to Tucker, shows a paper pallet designinvolving a folded corrugate sheet as the cargo support area. That cargodeck is provided with a number of pallet feet (which operate as spacerblocks within the cargo deck) made of molded plastic material such aspolystyrene. The use of a honeycomb core within the cargo support areais not disclosed.

U.S. Pat. No. 3,952,672, to Gordon et al, shows a disposable pallet madeof a single folded corrugated sheet. The use of a honeycomb core on thecargo support area is not disclosed.

U.S. Pat. Nos. 4,867,074 and 5,001,991, to Smith, each show a palletdesign in which the cargo deck is made up of a large number of girdersfolded from corrugated sheet and assembled with a series of crossgirders. The use of a honeycomb core in the cargo support area is notdisclosed.

U.S. Pat. No. 4,790,249, to Webb, shows a pallet design in which thecargo deck is made up of facing sheets separated by a number of blockshaving a specific design. The block design involves a cellulosicmaterial glued together by a bonding material (such as ureaformaldehyde)all extruded into the shape of a box beam. The boxes are positioned soto protect the deck from the tines on a fork lift.

Netherlands Patent Application 83-00024 shows an interesting design fora paper pallet. The cargo support deck appears to be constructed of anumber of loops of paper glued together at a number of sites within thedeck and also glued to a periphery forming the edge of the deck. Neitherthe use of a honeycomb core nor the use of corrugated sheet in the cargodeck support area is disclosed.

There are few disclosures showing the use of honeycomb materials in thecore of the cargo support deck.

One such disclosure is Published U.K. Patent Application 2,213,462-A toGreen et al. This published application shows a paper pallet design inwhich the cargo deck is made up of two face sheets of, e.g., corrugatedcardboard and having an open structure such as a paper or card honeycombbetween them. It is said that the deck may be raised from the floorusing feet of similar construction. The deck core is made to bepenetrable by the tines of a fork lift. There is no suggestion that thecorrugated sheets on alternate sides of the core should be positioned sothat the flutes are not parallel. Furthermore, the disclosure is silenton the use of a corrugated sheet folded over the edge of the centralcore and fastened to the opposite side, and the disclosure does notsuggest legs which are integral with the skin on the central core.

U.S. Pat. No. 4,319,530, to Moog, discloses a pallet, said to bedisposable, having a cargo supporting deck area made up of a centralcore of a honeycomb made of laminated corrugate. The core is faced withone or more corrugated sheets glued to the core. The facing on the cargosupport surface of the central core may be made up of multiple layers ofcorrugated sheets. Although these multiple facing layers are said to bepositionable so to permit "cross laminating where the flutes of thedifferent sheets are oriented at right angles", there is no suggestionthat use of corrugated sheets on alternate sides of the core positionedso that the flutes are not parallel is useful. Further, the disclosureis silent on the use of a corrugated sheet folded over the edge of thecentral core and fastened to the opposite side nor, obviously, is anybenefit accorded such a folded sheet.

None of these disclosures show a pallet constructed of paper involving acentral platform or deck constructed of a honeycomb filler bounded onthe top and bottom surfaces by corrugated sheets nor do thesedisclosures show the concept of using a folded corrugated sheet as boththe skins on the individual legs supporting the central core and on thebottom of the central core itself. These disclosures do not show thebenefit of increased torsional and deflective strength of the centralplatform via the use of carefully positioned corrugated sheets such thatthe corrugations or flutings in those face sheets are not parallel.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is an exploded drawing of the components of the basicconfiguration of the invention.

FIG. 1B shows an expanded partial plan of a corner of the FIG. 1A lowercover.

FIG. 1C shows a plan view of the lower cover of the pallet shown in FIG.1A.

FIGS. 2A and 2B are plan drawings respectively of the lower cover andthe upper facing sheet of another variation of the inventive pallet.

FIGS. 3A and 3B are bottom and top perspective views of a palletaccording to the invention.

SUMMARY OF THE INVENTION

In general, this invention is a pallet as might be used to support cargoduring that cargo's transportation or storage. The pallet is constructedof paper. The pallet design involves a central platform constructed of ahoneycomb filler. The bottom of the pallet is covered by a combinationof sheets (which may be corrugate) which are patterned in such a waythat the footblocks supporting the central platform are integral withthat central platform; that is, the footblocks (or legs) do not have aseam at their juncture to the central platform. Desirably the lowerportion is formed of two sheets; the bottom or lower cover sheet is cutand folded in such a way that it covers at least the footblocks and thesurface adjacent the bottom of the central portion. It is of the shapeof lower view of the pallet as the pallet is finally used. The othersheet is a lower or bottom facing sheet and is of the general size andshape of the bottom of the central platform with cutouts allowing thefootblocks covered by the bottom cover sheet to protrude through thatlower facing sheet. It resides adjacent the bottom surface of thecentral platform. The upper surface of the central platform is coveredwith a generally continuous sheet called the upper facing sheet. Theupper facing sheet may be a corrugate or heavy stock paper dependingupon its ultimate usage. To enhance the torsional and deflectivestrength of the central platform and thence that of the pallet, acorrugated sheet may be used as the upper facing sheet and positioned sothat the corrugations of the upper facing sheet and those of the lowerfacing sheet are not parallel. Additionally, the various corrugatedsheets may be folded over the edges of the honeycomb core and fastenedto another other surface. In addition to the inherent strength and lowcost of my pallet, by careful selection of construction materials, mydesign may be completely recycled as paper without separation intoconstituent parts.

Although the invention may be made of a variety of materials, I preferto construct the pallet from materials which may be readily recycledusing commercially available technology. For instance, the various sheetmaterial is desirably from kraft paper or other similar paper stock. Ofcourse, depending upon the service into which the pallet is placed,other materials may be selected, e.g., MYLAR, polyethylene,polypropylene (clear or fibrous paper product), or the like isacceptable. Some thermosetting polymeric materials are not currentlywidely recyclable and may not be the best of choices for the pallet fromthat viewpoint. However even with nonrecyclable materials theimprovements of the pallet design will be apparent. Choice of materialsand methods to join together the various components of the pallet mayalso be made on the basis of recyclability. For instance, mostwater-based glues, e.g., hide glue, mucilage, etc. are glues compatiblewith the kraft paper recycling processes. Heat sealing thermoplasticmaterials such as polypropylene is an expedient using no adhesive.

FIG. 1A is an exploded diagram showing the components of the basicconfiguration of the invention. The pallet in FIG. 1A has been turnedupside down to better show the components of the pallet and theirrelationship. In this configuration, the central core (100) comprises anexpanded honeycomb material having an upper surface, lower surface, andedges. The honeycomb's density and the thickness of the paper used aretwo engineering parameters which largely determine the strength of thecentral core and permit it to be used in this invention. If the methodfor joining the two facing sheets to the core is properly carried out,the cells within the core are isolated from each other. The corestrength is enhanced by the formation of these closed cells and impartsan amount of springiness and shock absorbing capabilities to the core.

Attached to the central core (100) are several footblocks (102, 104,106) which may also be an expanded honeycomb material. As analternative, these blocks may also be constructed from laminatedcorrugate if so desired. The configuration shown in FIG. 1A is a"four-way" pallet in that the vehicle used to move the pallet and itsload may enter the space beneath the central core from any of fourdifferent directions. The variation shown in FIG. 1A includes ninecornerblocks; corner footblocks (102) located at each corner of thecentral core (100), side footblocks (104) located at the approximatecenter of each side of the central core (100), a central footblock (106)located in the approximate center of the central core (100). Althoughthis configuration is without question one of the most likely to be usedcommercially, this invention also includes specialty pallets in whichonly the corner footblocks (102) are used. It is occasionally desirableto include sheets of paper (108) or other material between thefootblocks and the central core to serve as glue surfaces at the end ofthe passageways in the honeycombs in the footblocks and the centralcore.

The assembly comprising the central core (100) and the variousfootblocks (102, 104, 106) with the optional glue surfaces papers (108)is then covered with a carefully patterned lower cover (110). This lowercover is shown partially folded in FIG. 1A and is also shown in planview in FIG. 1C. The concept behind the shape of this lower cover isthat it forms a reasonably integrates lower view which does not presenta weak or seam at the junction of the footblocks to the central core andprovides a significant glue surface area between the cover and thecentral core. The absence of seams between the footblocks and thecentral core in addition to the fact that the skin on each of thefootblocks is also glued to the central core prevent s the feet formbeing easily severed from the central core by a misplaced forklift tineor the like. Said another way, because the lower cover (110) isfunctionally unitary as the skin of the footblocks and the lower skin onthe central core, the footblocks are very sturdy and likely will standmore abuse than any others in the paper pallet art. Because the lowercover (110) is most desirably a single piece, it may be placed in orfolded into an assembly form or jig, glue applied, footblocks insertedinto the relevant receiving areas in the lower cover, the central coreapplied, and the upper facing applied.888888

The sections of the lower cover and their functions are explained inconjunction with the blow-up in FIG. 1B. The portion marked "A" fits thebottom of the corner footblocks (102). The portions marked "B3" and "B4"are folded onto the cornerblock interior walls which reside between thebottom of the footblock and here the footblock meets the bottomside ofthe central core. Portion "B1" fits against the outside of the footblockand the outside edge of the central core. Portion "B4" is the same sizeand shape as is "B1" but also has glue tab "C1" attached in such a waythat it may be folded over and glued onto "B1". Similarly, tab "C2" maybe folded over portion "B3". Therefore, for each corner footblock, "A"forms the bottom and "B1", "B2", "B3", and "B4" form the sides of thefootblock. Portions "D1" (attached to "B2") and (attached to "B3")adhere to the underside of the central core (100) and are, in turn,attached to the underside of the central core (100) and are, in turn,attached to the other portions of the lower cover (100) which form thesides of the adjacent side footblocks (104). Portion "E" is a flap whichis glued directly to the underside of the central core (100).

A variation of the design of the lower cover (110) entails the conceptof assembling the cover from several pieces. For instance, two "mirrorimage" portions such as are to the right and left of lines of lines "x"and "y" imposed on the lower cover (110) in FIG. 1C. A central portionwould, as found between the two lines "x" and "y", also be necessary tocomplete the lower cover.

Completing the required portions of the lower end of the pallet is thelower facing (112). The lower facing (112) is cut in such a way that itfits over the assemblage of the various footblocks (102, 014, 106) afterthey have been concealed by the skin formed from the lower cover (110).Its edges fit up to the edge of the central core (100). It is glued tothe lower cover (110) and serves to further stabilize the footblocksfrom movement upon abuse and to impart excellent strength to the centralplatform and to the overall pallet.

The final portion of this variation of the inventive pallet is the upperfacing sheet (114). As is shown in FIG. 1A, upper facing sheet (114) hasa central area (116) which approximately corresponds in size and shapeto the upper surface of the central core (100). On each side of theupper facing sheet (114) are side portions (118) which fold down overthe sides of the central core (100) and the various footblocks (102,104, 106) which, of course, have been previously covered with lowercover (110). Various tabs are also provided to fold over the bottom sideof the lower facing sheet (120) and to fold around the outside cornersof the central core (100) and the corner footblocks (102) after theyhave been covered with the lower cover (110). The surfaces of the upperfacing sheet which are adjacent another piece of cardboard are glued tothose adjacent sheets. As was noted above, if the method for joining theupper facing sheet (114) is properly to the central core (100) isproperly carried out, the cells within the core honeycomb are sealed andare isolated from each other. The core strength is enhanced by theformation of these closed cells and imparts an amount of springiness andshock absorbing capabilities to the central core (100).

It is desirable, when both the lower facing sheet (112) and the upperfacing sheet (114) are corrugates, to position the respective sheetssuch that the flute s in the corrugate of lower facing sheet (112) arenot parallel to the flutes in upper facing sheet (114). The anglebetween the respective flutes may vary between about 30° and 90°although for a very practical pallet from the vantage of strength,versatility, and ease of construction, an included angle between theflutes of about 90° is desirable.

Central to this invention are the following:

a.) the lower cover (110) covers the majority of the underside of thecentral platform (100), covers the exterior of the footblocks attachedto the central platform, has no edges adjacent the juncture the of thefootblocks and the central platform, is functionally continuous betweenadjacent footblocks, and adheres to the bottom of the central deckbetween the footblocks, and

b.) the lower facing sheet (112) is cut in such a way that it fits overthe assemblage of the various footblocks (102, 104, 106) after they havebeen concealed by the lower cover (110). It is glued to the lower cover(110).

This invention is not limited to the basic variation shown in FIG. 1A.FIG. 2A shows a variation in which the lower cover (200) (the analog oflower cover (110) in FIG. 1A) has tabs (204) which fold over the edge ofthe center core or deck. The corresponding upper facing sheet (202), asshown in FIG. 2B, has tabs (206) which fold over tabs (204). Thisresults in a visible seam on the edge of the central core. The variationshown in FIG. 1A has a visible seam on the underside of the centralcore. It is within the scope of this invention to have the various tabsenclosing the central core configured so that the visible seam is on thetop of the central platform. Each variation has its benefits anddetriments. For instance, the seam on the top of the pallet will form asmall ridge which can be used to help maintain certain types of cargo,e.g., loosely bagged bulk materials, etc., in place on the upper side ofthe central deck.

FIGS. 3A and 3B show perspective lower and upper views of the inventivepallet shown in exploded view in FIG. 1A.

The pallet may be coated with a material which will harden or waterproofor dustproof the pallet. These materials may be chosen to meet whatevercriteria are appropriate for the pallet use. For instance, if used in ahumid atmosphere or used outside or are moved between refrigerated andnon-refrigerated areas, waterproofing is desirable. Known water-basedand oil-based materials may be applied as needed.

Additionally, the cargo face of the deck may be covered with or coatedwith a suitable material to prevent slippage of the cargo.

When the pallet of this invention is used in conjunction with rollerconveyer systems, a hard paperboard may be glued to the bottom of thecovered footblocks. The paperboard is typically one-fourth to one-halfinch in thickness and made form thin sheets of paper glued andcompressed together to give a hard surface to the bottom of the runners.The hard surface prevents the bottom of the corrugate trays fromdepressing around the conveyer roller and thereby preventing theload-bearing pallet form rolling easily down the conveyer. The hardpaperboard provides adequate hardness for reducing the compressibilityof the runner bottom and therefore reduces the drag on the pallet.

The invention has been described by description and by example. Theexamples are just examples and are not to be used to limit the scope ofthe invention in any way. Additionally, one having ordinary skill inthis art will recognize variations and equivalents within the inventionas described which will not necessarily be within the scope of theappended claims.

I claim as my invention:
 1. A pallet comprising:a honeycomb platform having an upper surface, lower surface, and edges; an upper facing sheet adherent to the upper surface of the honeycomb platform, footblocks adherent to the lower surface of the honeycomb platform, a lower cover patterned so that it comprises portions that cover the footblocks and portions that cover the lower surface of the honeycomb platform, said cover is functionally continuous between adjacent footblocks, and is adherent respectively to the lower surface of the honeycomb platform and the surfaces of the footblocks it covers, said portions that cover the footblocks extending downwardly from said portions that cover the lower surface of the honeycomb platform and a lower facing sheet patterned with openings so that said portions that cover the footblocks protrude through the openings in the lower facing sheet and which lower facing sheet adheres to the portion of the lower cover sheet which adheres to the lower surface of the honeycomb platform.
 2. The pallet of claim 1 where the composition of one or more of the honeycomb platform, upper and lower facing sheets, and lower cover sheet is selected from paper, MYLAR, polyethylene, polypropylene (clear or fibrous paper product).
 3. The pallet of claim 2 where the composition of one or more of the honeycomb platform, upper and lower facing sheets, and lower cover sheet is selected from paper.
 4. The pallet of claim 1 where at least one of the upper facing sheet or lower cover sheet is folded over and adherent to the edge of the honeycomb platform.
 5. The pallet of claim 1 where the honeycomb platform is adhesively connected to the upper facing sheet and the lower cover sheet so a substantial portion of cells within the honeycomb platform are sealed.
 6. The pallet of claim 1 said footblocks including corner blocks located at corners of the honeycomb platform.
 7. The pallet of claim 6 said footblocks including side footblocks located at the approximate centers of the sides of the honeycomb platform.
 8. The pallet of claim 7 said footblocks including a center footblock located at the approximate center of the honeycomb platform.
 9. The pallet of claim 8 where the footblocks comprise expanded honeycomb.
 10. The pallet of claim 1 where the upper facing sheet and the lower facing sheet are corrugate.
 11. The pallet of claim 1 where the corrugates have flutes and the upper facing sheet and the lower facing sheet are positioned so that the upper and lower flutes are not parallel to each other.
 12. A paper pallet comprising:an expanded paper honeycomb platform having an upper surface, lower surface, and four edges with corners; a corrugate upper facing sheet adherent to the upper surface of the honeycomb platform which corrugate has flutes; corner footblocks adherent to the lower surface of the honeycomb platform and positioned at the honeycomb platform corners; a lower cover sheet patterned so that it comprises portions that cover the footblocks and portions that cover the lower surface of the honeycomb platform, said cover is functionally continuous between adjacent footblocks, and is adherent respectively to the lower surface of the honeycomb platform and the surfaces of the footblocks it covers, said portions that cover the footblocks extending downwardly from said portions that cover the lower surface of the honeycomb platform and a corrugate lower facing sheet having flutes and patterned so that said portions that cover the footblocks protrude through the openings in the lower facing sheet and which the lower facing sheet adheres to the portion of the lower cover sheet which adheres to the lower surface of the honeycomb platform and positioned so that the upper and lower facing corrugate flutes are not parallel to teach other.
 13. The pallet of claim 12 additionally having side footblocks located at the approximate centers of the sides of the honeycomb platform.
 14. The pallet of claim 13 additionally having a center footblock located at the approximate center of the honeycomb platform.
 15. The pallet of claim 12 where the honeycomb platform is adhesively connected to the upper facing sheet and the lower cover sheet so a substantial portion of cells within the honeycomb platform are sealed. 